You said you can see the publishers on the PC, right? If that is the case: read further...
1st step (It is probably not necessary to do this, but better safe than sorry) On the PC open TB and in Settings, click Open Database location. Find the file called theocbase.sqlite (exactly that) and copy it somewhere safe.
In TB now go to the cloud symbol where you normally synchronise, but do not click it. Hover over it and in the fields that become visible, click 'remove data from cloud' at the bottom. "Are you sure?" "Yes".
After only 1 or 2 seconds it will ask you if you want to synchronise. Click "Yes". Your local data will now be uploaded to a new cloud file, which essentially means the cloud data were reset.
If now you try to sync from another device, it will throw a warning to users that the cloud data were deleted. This might sound like there are no cloud data, but of course those were rebuilt after deletion. So go ahead and sync.
If you still have issues, we can try one more thing, but depending on the number of users that requires some coordination.